[Parity]: OperationEndInfo should exposes serialized-result accessor

[wangyb-A]

Expected Behavior

OperationEndInfo exposes no serialized-result accessor — plugins cannot see an operation's checkpointed result at operation-end (error side works via error()). Python/JS both surface it.

Actual Behavior

We should include the result in the hook param

Steps to Reproduce

#581

SDK Version

2.0.0

Java Version

17

Is this a regression?

No

Last Working Version

No response

Additional Context

No response